1in July, 1966, Dr. Gao Kun of British Institute of Standard Telecommunications and Hawkham, a British Chinese, published a paper with great historical significance on the prospect of optical fiber transmission. This paper analyzes the main reasons for the large loss of glass fiber, and boldly predicts that as long as the impurities in glass fiber can be reduced, it is possible to reduce the fiber loss from 1000 dB/km to 20db/km, which can be used for communication. This paper has inspired many scientists to make efforts to realize low-loss optical fiber.
1970, after many experiments, Dr. Capron from Corning Glass Company of the United States finally developed an optical fiber with a transmission loss of only 20 dB per kilometer. Such low-loss optical fiber was an amazing achievement at that time, which made the realization of optical fiber communication possible.
1970, Bell Institute of America developed a semiconductor laser which can work continuously at room temperature. This laser is only the size of a grain of rice. Although the original laser has a short life, it has always been considered as the light source of optical fiber communication. Due to the breakthrough of optical fiber and laser, optical fiber communication is possible. Therefore, 1970 is considered as the memorable first year of optical fiber transmission.
1970, two technical problems of optical fiber and laser were broken, and optical fiber communication became possible from ideal. Telecommunications scientists and technicians from all over the world compete for research and experiments. Optical fiber communication began to enter the practical stage, and has developed very rapidly since then, and its application system has been updated many times. The optical fiber communication system in 1970s mainly used the short-wave band of optical fiber for transmission. After the 1980s, it gradually switched to long-wave band; By the early 1990s, the communication capacity of optical fiber had expanded by 50 times. In the late 1990s, the transmission wavelength was longer, and new technologies such as optical fiber amplifier were adopted to enhance the signal and expand the transmission capacity. At this time, optical fiber is widely used in local telephones and long-distance communication trunk lines, becoming the backbone of communication lines. Even eight countries, including the United States, Japan, Britain and France, have announced that in the future, long-distance communication trunk lines will be laid with optical cables instead of cables.